The present invention relates to an engine starting apparatus with an antitheft function. More particularly, the present invention relates to an engine starting apparatus, with an antitheft function, suitable for use with a motorcycle which includes a kick-starting mechanism.
Some engine startup devices including anti-theft features are known. An immobilizer of the transponder type, which utilizes an authentication code, is known for use as a vehicle antitheft apparatus, such as that disclosed in Japanese Laid-Open Patent No. 2000-329041. The immobilizer described in this reference is used as a substitute security device in place of a conventional lock apparatus of the mechanical locking type, such as a handlebar lock apparatus and a wheel lock apparatus.
In an immobilizer of the type described in the reference, an authentication code, registered in advance in an ignition key or a portable terminal module, is transmitted toward an authentication apparatus attached to the vehicle body side. If the authentication code coincides, or has a predetermined relationship with an authentication code registered in advance in the authentication apparatus, then starting of an engine is enabled. However, if they do not coincide with each other, or do not have the predetermined relationship, then starting of the engine is prevented.
In the apparatus disclosed in Japanese Laid-Open Patent No. 2000-329041, the authentication apparatus receives power from a power supply carried on the vehicle body. Accordingly, if sufficient power is not supplied to the authentication apparatus, because of a drop of a battery voltage or the like, then verification of the authentication codes cannot be performed. Particularly with a motorcycle, since a battery carried thereon often has a comparatively small capacity, a drop of the battery voltage must be considered.
A technique is disclosed in Japanese Laid-Open Patent No. 2002-370621 to make it possible to authenticate an authentication code, even in a condition where the battery voltage is low. This technique divides an authentication procedure of a code in a motorcycle which includes a kick-starting mechanism into three stages, and advances the authentication procedure by one stage by one kick operation. Accordingly, starting of the engine is allowed after three kick operations.
According to Japanese Laid-Open Patent No. 2002-370621, mentioned above, starting of the engine is permitted only after the validity of an authentication code is confirmed. Thus, even if a generator is driven by a kick-starting mechanism, and driving power is obtained thereby, the power obtained by the first kick is all consumed in the authentication procedure of the authentication code. Consequently, the engine cannot be started by the first kick, but at least three kick operations are required before the engine is started.
Although the known devices have some utility for their intended purposes, a need still exists in the art for an improved authenticating apparatus for a motorcycle. In particular, there is a need for an improved authenticating apparatus which ensures security, yet which enables a user to start an engine in a shorter period of time than the previously known technology.